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Coronary rupture to the right ventricle during
PTCA for myocardial bridge
“Miyokardiyal Bridge” tedavisinde uygulanan PTKA s›ras›nda
koroner arterin sa¤ ventriküle rüptürü
Ergun Demirsoy, Harun Arbatl›, Mehmet Ünal, Naci Ya¤an, O¤uz Y›lmaz, Faruk Tükenmez,
Deniz fiener*, Bingür Sönmez
Departments of Cardiovascular Surgery and *Cardiology, ‹stanbul Memorial Hospital, ‹stanbul, Turkey
Address for Correspondence: Ergun Demirsoy, MD, Necip Bey Sok. Melen Apt. 6/6 34718 Ac›badem, ‹stanbul, Turkey
Tel./Fax: +90 212 220 89 10 E-mail: ergundemirsoy@hotmail.com - edemirsoy@superonline.com
Case Report
Olgu Sunumu
Introduction
Myocardial bridge (MB) is a congenital abnormality of the coronary arteries characterized by the decrease in the coronary blood flow during systole due to the compression of the myocar-dial fibrils surrounding the epicarmyocar-dial coronary artery in a certa-in segment. Although usually asymptomatic, medical therapy, percutaneous transluminal coronary angioplasty (PTCA), and ra-rely surgery may be necessary to relieve symptoms.
Case Report
A 37 years old male patient was admitted to another hospital with the complaint of chest pain on exertion. Myocardial perfusi-on scintigraphy revealed anterior and anteroseptal ischemia. Co-ronary angiography proved presence of MB causing 70-80% ste-nosis in the middle segment of the left anterior descending coro-nary artery (LAD) during systole (Fig. 1). The existence of a MB was confirmed with intravascular ultrasonography (IVUS), which also revealed a plaque creating 80% stenosis just distal to the bridge (Fig. 2). A percutaneous transluminal coronary balloon an-gioplasty with concomitant implantation of a stent was the first intention for treatment by the cardiologist. During the inflation of the PTCA balloon; the vessel wall of the LAD ruptured acciden-tally to the right ventricle (Fig. 3), but was further successfully fi-xed with the implantation of a graft-stent (Jostent®, JoMed
GmbH, Rangendingen, Sweden). Six weeks later, he was admit-ted to the same hospital with unstable angina. A new coronary angiography revealed a 90% stenosis, which was due to a throm-botic lesion within the stent, and 80% stenosing plaque was still observed in place distal to the stent (Fig. 4). The patient applied to our hospital and surgery was arranged since he had unstable angina and no more chance for another stenting. We performed a coronary bypass operation (CABG) with the left internal mam-mary artery (LIMA) to the LAD graft. The patient had an unevent-ful recovery and early postoperative stress tests demonstrated no evidence of ischemia.
Discussion
In anatomical studies, the prevalence of myocardial bridge is reported to be varying between 5.4% and 85.7%, but in angiog-raphic studies, the prevalence is 0.5% to 4.5% (1). In one study, coronary angiographies performed in 2547 Turkish patients reve-aled the presence of MB in 26 patients (1.02%) (2).
Usually located in the mid-LAD, myocardial bridges com-monly are asymptomatic but may rarely present with angina pec-toris (3), myocardial infarction (3), life-threatening arrhythmias or even sudden death (4).
Considering that the major myocardial perfusion occurs du-ring diastole, the narrowing of the coronary lumen dudu-ring systo-le should not normally cause ischemia, but Schwartz and colsysto-le- colle-agues, using intracoronary Doppler ultrasonography and angiog-raphy proved that systolic narrowing persists up to the mid-dias-tolic phase and this may be the reason of the perfusion failure and of ischemia (5).
Beta-blockers and calcium-channel antagonists are prescri-bed to relieve angina by decreasing the heart rate and the myo-cardial contractility, whereas nitrates are not suggested due to a possible augmentation of symptoms caused by the decrease of coronary vascular wall tension (3).
Jeremias and colleagues have reported a case where they could hardly prevent the systolic compression with the implanta-tion of four consecutive stents in a patient with myocardial brid-ge, and an evolving dissection in the coronary artery after PTCA (9). Another case of a myocardial bridge with the formation of a thrombus within the coronary artery after stenting was reported by A¤›rbafll› and colleagues (10).
In a case reported by Hering and colleagues, perforation of the coronary artery to the right ventricular outflow tract due to balloon oversizing occurred during balloon angioplasty of a myo-cardial bridge . The patient was referred for medical treatment and follow-up, and control angiography performed three months later showed spontaneous closure of the fistula (8).
In cases where the LAD is located intramyocardially, this segment of the artery is normally in direct relationship with the right ventricular cavity. In cardiac surgery this relationship is qu-ite clear, that opening of the right ventricular cavity is the most common complication during dissection of an intramyocardial
LAD. It should be kept in mind that during PTCA procedure, due to high wall tension created by the balloon, the posterior wall of the LAD without myocardial support would be the segment most prone to trauma and may result in a rupture to the right ventricle easily. Especially in the presence of a plaque, risk of rupture of the LAD to the right ventricle is higher since more pressure is ne-cessary in the balloon.
Figure 1. Coronary angiography showing the myocardial bridge in the mid-LAD. A- Normalization during diastole (arrow) B- Systolic compression of the epicardial artery (arrow)
LAD - left anterior descending artery
Figure 2. Intravascular ultrasonography demonstrating the bridge in systole and diastole
Figure 4. Control angiography 6 weeks after stenting showing subtotal ste-nosis within the stent (arrow) and an 80% stenosing plaque (dotted arrow) distal to it
Figure 3. A- Coronary angiography showing extravasation of contrast medi-um to the right ventricle (arrow) as evidence of rupture of the LAD. B- Zoomed image of the extravasation
Anadolu Kardiyol Derg 2006; 6: 377-9 Demirsoy et al.
Coronary rupture and myocardial bridge
Conclusion
In cases where a myocardial bridge is detected angiograp-hically, if angina pectoris persists despite medical treatment, and there is evidence of ischemia in stress tests, IVUS should be performed to detect any accompanying atherosclerotic disease. Despite reports of successful PTCA in the treatment of MB, es-pecially in the presence of accompanying atherosclerosis, beca-use of the extremely thin nature of such vessels, and a high risk of complication such as rupture to the right ventricle, surgical supraarterial myotomy should be the first choice of treatment.
References
1. Angelini P, Trivellato M, Donis J, Leachman RD. Myocardial brid-ges: a review. Prog Cardiovasc Dis 1983; 26: 75-88.
2. Soran O, Pamir G, Erol C, Kocakavak C, Sabah I. The incidence and significance of myocardial bridge in a prospectively defined popu-lation of patients undergoing coronary angiography for chest pain. Tokai J Exp Clin Med. 2000; 25: 57-60.
3. Faruqui AM, Maloy WC, Felner JM, Schlant RC, Logan WD, Symbas P. Symptomatic myocardial bridging of coronary artery. Am J Car-diol Jun 1978; 41: 1305-10.
4. Kracoff OH, Ovsyshcher I, Gueron M. Malignant course of a benign anomaly: myocardial bridging. Chest 1987; 92: 1113-5.
5. Schwarz ER, Klues HG, vom Dahl J, Klein I, Krebs W, Hanrath P. Functional characteristics of myocardial bridging. A combined an-giographic and intracoronary Doppler flow study. Eur Heart J 1997; 18: 434-42.
6. Demirsoy E, Arbatl› H, Ünal M, Tansal S, Yagan N, Korkut K, et al. Surgical approach in myocardial bridging :supracoronary myoto-my. J Turkish Thorac Cardiovasc Surg 1999; 7: 438-41.
7. Kurtoglu N, Mutlu B, Soydinc S, Tanalp C, Izgi A, Dagdelen S, et al. Normalization of coronary fractional flow reserve with successful intracoronary stent placement to a myocardial bridge. J Interv Car-diol 2004; 17: 33-6.
8. Hering D, Horstkotte D, Schwimmbeck P, Piper C, Bilger J, Schult-heiss HP. Acute myocardial infarct caused by a muscle bridge of the anterior interventricular ramus: complicated course with vas-cular perforation after stent implantation Z Kardiol 1997; 86: 630-8. 9. Jeremias A, Haude M, Ge J, Gorge G, Liu F, Konorza T, et al.
Emer-gency stent implantation in the area of extensive muscle bridging of the anterior interventricular ramus after post-interventional dis-section Z Kardiol 1997; 86: 367-72.
10. Agirbasli M, Hillegass WB, Chapman GD, Brott BC. Stent procedure complicated by thrombus formation distal to the lesion within a muscle bridge. Cathet Cardiovasc Diagn 1998; 43: 73-6.
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